Perhaps it's from seeing a few too many homes in the 1990's look like this:
There's a lot of red, and a lot of brown... and all together it equals... just a lot. Too much. I call this look "faux elegance".
That said, I have a real appreciation for this loud color when used in the RIGHT way. For me, that would be in accessories. More specifically, I could really see myself incorporating this color through a Persian rug... but not an uber traditional rug - one with more of a tribal print. I swear I'm not trying to be vague!! If you're not entirely sure what I'm talking about, check out Jenny's (of the Little Green Notebook):
Here are some other good examples of using red Persian rugs without going overboard...
This hallway had me at hello... white adobe walls, substantial wooden beams. It's classic Spanish style meets the middle east, and the punch of red on this flat woven rug is absolute perfection...
Again... here we have a nice neutral kitchen, and the red runner just wakes things up a bit (plus, whatever gets spilled on this rug will disappear instantaneously with all the dark colors and pattern)
Contemporary Family Room by New York Architects & Designers BWArchitects (formerly Basil Walter Architects)
I love this pair of rugs in the library. With a full wall of books, it's hard to go wrong here, but they just add a global element, and having a more simple, large diamond pattern in the area rug isn't too busy against all the book spines.
This rug isn't Persian - it's more southwestern, but I love it. Again, who would think to put a large rug like this in a kitchen?? Not that many people, but with so many spills, it's genius! Just don't put an heirloom in there...
So what is my conclusion about red?
When done in small doses, it's amazing!
I'd go for red rugs with a global feel (Persian or Southwestern seem the safest). More graphic patterns are also easier and at all costs, stay away from any red rug that looks "faux Tuscan villa", or "old European" in any way shape or form.